Friday, January 28, 2011

Melinda and I took a late afternoon drive last week to "A" Mountain (Sentinel Peak), up in the foothills of the Tucson Mountains overlooking the Tucson Valley from the west. As you can guess from the name, there is a big "A" on the slope, for the local U of A, or in case anyone forgets what state they're in! In any event, it is a popular destination to check out the view of the city till it closes in the evening (mountain access, that is...).

The reason for our visit was to take some photos in the growing twilight. I'd been corresponding with our friend Dick, who has gotten me into making panorama images. I took a series of vertical format shots with the Canon XSi and the 70-200mm lens set to about 150mm, 1.3 seconds at ISO 200. The 5 images were stitched automatically in Photoshop, and viola, a panorama! At it's native resolution of nearly 12,000X4000 pixels, it is easy to get lost roaming around the environs of downtown Tucson and the University. Unfortunately, our blogging software limits the picture to 1600 pixels wide, so you can't enjoy the same tour, but I can show you selected highlights! Be sure to click on the images for the full-size views...

Just like playing "Where's Waldo", looking out of place for what counts as skyscrapers in Tucson is the tile dome of the old Pima County Courthouse, built in 1929 in Spanish Colonial Revival style. It is now surrounded by newer court buildings, but the old courthouse certainly adds a bit of class to the boxy structures of the city. The only time I've been in it was to collect juror pay a couple decades ago, and I think it now serves as offices for the county treasurer and recorder.

Just above the courthouse in the large shot above is Melinda's workplace, the University Medical Center. The large building on the left is the new Diamond Children's Center, named for Don Diamond, a local developer. Melinda works at the NICU on the 4th of 6 floors - green lights on top are for the heliport. The building to the right is the main building of UMC, where I've spent lots of time the last few years, it seems!

The last of the "highlights" is a recognizable landmark - Arizona Stadium! Of course, I work under the east stands at the Mirror Lab, unfortunately not visible from the west. Space under the west stands, also unfortunately not visible behind new dormitory construction, is the Laboratory of Tree Ring Research, interestingly, started by the same fellow who started Steward Observatory in the early years of the last century- A.E Douglas! What is interesting to me is that the 18" high letters that spell "ARIZONA" is resolved from the 4 miles or so distance to our observing spot in the camera lens.

While it is fun cruising around the full resolution version, I was mystified by the wiggling headlights of the cars. If you look closely at the headlight streaks in the 1.3 second exposures, they oscillate over part of the exposure. In exchanges with some of Dick's friends, it seems that the mirror and shutter slap in the camera causes some low-level vibration even though a tripod was used. In future attempts I'll try mirror lockup to minimize the effect. It didn't seem to affect the overall sharpness too much, though...

And just to show that we were indeed on A Mountain, as we turned to leave we took a shot of the "A". It used to be painted white, but since 9/11, it has been red/white/blue. The color has not been without controversy, since groups paint it green on St Pat's Day, and if they don't get caught, marauding ASU students try to paint it it maroon and gold before their Fall football matchup. There has been some call for a return to white, myself among them, but we're still waiting... The bright object in the upper corner is Jupiter, still dominating the western sky.

Sunday, January 23, 2011

We know our regular readers in the Midwest, mostly friends and family, have been suffering through some of the coldest temperatures, and worst winters in recent memory. Well, I've been good so far about not bringing up the weather here, but it is about time to say - NYAH, NYAH! Since the start of the year, we've had remarkably consistent weather, high temps in the upper 60s to low 70s, approaching 80F at one point! On clear nights the lows still drop down to the mid 30s, so it is still pretty cool at night, but with remarkably warming during the day. And in the last month, the sunset is now over 30 minutes later, so there is time to get a walk in after work with the sun still up.

These shots were taken Saturday - the first time I've worn shorts this year on my stroll. Photo options were limited, low sun, not much in the way of interesting greenery since even our spring is a couple months away, but I couldn't decide between the two shots, so you get them both. A pair of self portraits with my new Droid-X phone camera.

More of the same expected this week temperature wise - also no rain - our last precipitation was 30 December (we got a whopping .5" in December!), nor any expected the rest of this month. Pretty dry compared to last year, when it seemed to rain every few days! Still, not a bad way to spend a Winter...

Tuesday, January 18, 2011

Our friend Dick was visiting Tucson from LA this last weekend, and we met down in Willcox, AZ, where he lived until a few years back. It was the weekend of the local celebration "Wings Over Willcox" (WOW!), a nature and birding festival, mostly triggered by the annual migration of Sandhill Cranes, who winter in nearby fields and riparian areas.

We met Dick, girlfriend Nancy, his daughter Elizabeth and her husband at the Willcox Community Center. While relatively small, there was a huge turnout of local attractions (Chiricahua National Monument, Amerind Foundation), as well as professional wildlife photographers, artisans and conservation groups. As soon as we traded greetings, a woman from Gray Hawk Nature Center handed Nancy a cornsnake, and offered to take group pictures, as well as talk about snakes and other "scary" resident creatures and the good they do for ecology. And while I got my "ultimate" closeup of a Sandhill Crane, it was, indeed, a stuffed version of the beast...

However, another group had a collection of rehabilitated birds of prey that had been injured and could not be released into the wild (supremely unstuffed!). Most magnificent of these was a 24-year-old bald Eagle named Libby. Libby had been shot long ago and had her left wing partially amputated and relegated to education programs. She was a beauty, though she was uncomfortable with my getting too close with the camera and she showed her displeasure! She liked Melinda much better, so she took these pictures. Also in the bird collection was a Western Screech Owl and American Kestrel, among others - all just spectacularly beautiful!

Finally, it was time to head out and see some cranes! Normally, Melinda and I head down to Whitewater Draw, where large numbers of the birds congregate. However, it is a good 45 minute drive from Willcox, so we headed out for the 12 minute drive out near the Apache Generating Station. There are areas of standing water and an observation berm for viewing. This location didn't have the sheer numbers or proximity to the cranes, but it was fun to get Dick and Nancy out birdwatching with us. In the picture of the cranes, there are also some interesting mirage effects of distant buildings off the warm air of the Willcox Playa. even though there is no water on the flats, the warm air layer reflects blue sky making it look like a body of water.

Dick and Nancy headed back to Tucson to meet up with friends, and Melinda and I took the scenic route back, exploring some back roads, but it is always a great day being out and about on a warm winter day!

Friday, January 14, 2011

The word came quietly today. Karen, who has been at the Lab since about day 1, came around to us "old timers" to let us know that Eric had died yesterday of cancer. He, too, had been up the street at Steward Observatory seemingly forever, working in the drafting department. After getting his lung cancer diagnosis 2 years ago last fall, and given 6-12 months to live, he retired to get treatments, and spend time with his wife Kirsteen raise their son Brendon, now 6.

And that might have been the last time I would see him, but for the chance meeting we had at University Medical Center we had a year ago or so. Both of us were wandering the halls after tests or whatever, and we stopped and caught up, finding that we were both blogging, and reconnected because of it. The regulars might have seen his listing on the right border of our blog "Arizona Imagined", which contains some of the most impressive writing and imagery of the Southwest that I've seen! That boy got around and had himself some adventures! I invite all of you to take a little time and read what he had to say, and see what he saw in his explorations.

We were not close - acquaintances at work, but on a first name basis. We commented on each others blog posts, and I accepted his blog's invitation to come to Brendon's 6th birthday last April. I've not been to a 6-year old's party since about the time I was 6, and it was a fun time. He even sacrificed himself to be the target of 25 kids with boxes of water balloons!

And now we've only got his memory, and his blog where he shows his love of the Arizona desert, and the love he has for a 6-year-old who will now continue without his dad. These pictures at left are among my favorites of him and Brendon from his blog, taken, interestingly, in Chicago near us last summer where they were attending a relatives funeral, then playing tourist in the Windy City.

Tuesday, January 11, 2011

Just one more post from our trip to Geology Vista last Saturday. Even though we were only there for a couple hours (set up in snow and very treacherous ice), we accomplished 3 mini-projects. Besides the objective prism shot of the Hyades and the closeup of Achenar (last 2 posts), we also took advantage of a very pretty lunar crescent and Melinda's camera's HD video capability and took a short movie tour of the moon.

The effects of atmospheric seeing can be noticed, but it isn't too objectionable at this scale, taken with the Celestron 14". The effective focal length is about 4 meters, so consider the scope a telephoto lens of about 4,000mm focal length. Melinda's camera is the Canon T1i, which is one of the first allowing HD video. We grabbed 3 frames from the clip and pieced together the following mosaic. If we were more ambitious, we'd annotate it to label some of the features, but we can't do it all for you! If enough of you complain in the comments, we'll add some... And yes, we noticed after the fact that we missed the southern cusp!

Sunday, January 9, 2011

I've mentioned the Green Flash before - it is normally a vivid spot of green that becomes visible as the last piece of sun remains on the horizon. I've also talked about how it is formed in a previous post about imaging crescent Mercury (shown at left here). At very low angles above the horizon, the atmosphere acts like a thin prism, and as I demonstrated in last night's post, a prism will break the light into the colors of the rainbow. So the atmosphere does the same thing - the upper edge of an astronomical body, be it the sun, a crescent Mercury or a star, appears bluish or green, the lower edge appears red. This is a different effect than a rising or setting sun or moon appearing reddish - that is just the longer path length through the atmosphere of a low object scattering the shorter wavelengths more.

Most amateur astronomers are familiar with telescopic views of the planets or Moon when they hang low in the sky. The side nearest the horizon is reddish, the higher side blue. Again, this is caused by atmospheric dispersion. But the disk of a planet or moon is still mostly white. A star, however, not showing a true disk, can take on the appearance of a spectrum, especially if it is very low in the sky.

I've been waiting a few months to document this observation, and Saturday everything came together to take a picture of Achernar, the 10th brightest star in the sky. The reason you likely haven't heard of it is that it is a southern hemisphere object, located at -57.25 degrees south, meaning that from Geology Vista's 32.4 degrees north latitude, it clears the horizon by less than half a degree (90-32.4=57.6). Being up on a mountain helps, and the atmosphere helps too by making it appear higher than it would be from an airless world by about a half degree. So Achernar should appear less than 2 degrees at it's highest. It was visible to the naked eye twinkling over the lights of Vail 25 miles to the south as the twilight glow faded in the southwest.

But in a telescope, as the light travelled through more than a dozen times a single air mass, it was transformed into a living writhing (from atmospheric turbulence) spectrum, red at the bottom, blue on top. There was no colorless disk - the point of the star was a pure spectrum, transformed by the prismatic effect of the Earth's atmosphere. Shown here is a stack of 10 frames, each 2 seconds duration, which gets close to the visual effect of the low star. This is slightly cropped from an image with the C-14 telescope, about 4,000mm focal length.

Back in the "olden days" at the University of Iowa working at the observatory, we observed stars low in the sky, to calibrate the atmospheric transmission as a function of wavelength and air mass. Oftentimes we noted the transformation of star images into little spectra, and we had to note which part of the spectrum we were observing at any time to make sure that star's color was going into the slit. Observing and documenting the effect certainly brings back memories of those days!

Saturday, January 8, 2011

It started with an e-mail Friday. An author of an upcoming astronomy text found me on the Internet from a picture of the Hyades star cluster I had taken a decade or more ago for McDonald Observatory. I had made a prism out of flint glass, and experimented some with objective prism spectroscopy. After Googling it, mine was about the only image that popped up, even though it was pretty lousy, from way back in the film days. Anyway, he was asking if it was copyrighted anywhere, or if he could use it for his book. The old picture is shown here.

My thinking was that it could be greatly improved with modern cameras and detectors, so after digging the prism out of my "storeroom", I modified it for my digital camera and telephoto lens. After a test in the backyard last night on Sirius, Melinda and I headed up to Geology Vista in the mountains north of town in search of darkish skies (moon was out, so didn't need a long trip!). After setting up the tracking mount (G-11), The Hyades star cluster was centered, the proper zoom setting located (about 150mm), and the exposure fine tuned (45 seconds, ISO 800), and technique practiced (driven north at slowest rate during the exposure to widen spectra). The "V" shape of the Hyades cluster is evident, though the orientation is rotated 90 degrees from the old image atop the page. The bright star is Aldebaran, a K5 giant.

The results I thought were quite spectacular! Not only were the stars spectral colors nicely displayed with the Bayer-matrix detector of the Canon camera (XSi in this case), but unlike the old film image, the spectral absorption lines were readily visible in nearly all the stars. The dark lines silhouetted on the spectra indicate the chemicals and their abundances in the distant stellar atmospheres, and can be used to determine temperatures of the stars as well. Shown here is a blow-up of the above image, zeroing in on Theta 1 (above) and Theta 2, a multiple star and members of the cluster. The upper star is a K0III, a cool giant star where many absorption lines show the makeup of it's atmosphere. The lower is an A7III, whose hotter temperatures and few strong lines show mostly hydrogen in it's atmosphere.

Objective prism spectroscopy in combination with wide-field Schmidt telescopes was used extensively for surveys of stellar spectral types, and more recently just a couple decades ago for galaxy surveys. The ability to see the spectra of many objects at once was a very efficient way to work. Now days it is used less, but it is a fun and new way to see the sky in a new light!

Friday, January 7, 2011

Being an avid "Facebook"-er, I was more than interested when one of my cousins in the Los Angeles area posted that she was hostessing a knitting gathering at the end of January. She described knitting or crocheting 8" squares to send to Africa, where they would be made into blankets and given to orphans. While I enjoy knitting and crocheting, I don't always have the patience to make a sweater or afghan, so making an 8" square is right up my alley! She also posted a link to this web site: "Knit a Square"
I mentioned my interest in doing this to one of my friends at work, Jenny. She thought it sounded like fun and asked to join forces with me. From there we set about organizing a knitting group - which Dean dubbed a "Knit-In". While we put this group together on short notice, we still had 2 people (besides ourselves) interested. I approached one of our local coffee houses, "The Coffee X Change", to ask if we could meet there. They were very enthusiastic and welcoming of our business telling me that they have a Chess Club that meets there every week, as well as other clubs that also meet there regularly. So, today was the day of our first Knit-In! Unfortunately, the only picture I have of our group I took with the camera on my phone. We were too busy knitting to pose for pictures! Featured in the picture are (from left to right): Jenny, Åsa, and Sue (I was taking the picture). We all brought yarn, knitting needles, crochet hooks, and anything else we may need. I think we had enough yarn to make a blanket for every baby in Africa! We are keeping in mind that these blankets are for children, so we want them to be colorful and cheerful! After 4 hours of work (in which we shared stories, coffee, and lunch) our total was 12 squares completed! Our goal is to get as many squares together that we can so that they can all be shipped together. Some of our friends who weren't able to join us today have been busy knitting and crocheting, so we'll gather all together for a shipment before we meet again in a month.
I would imagine that some of you, out there, may also be interested in becoming involved in this project. Please, go to the "Knit a Square" website and read about this very worthwhile charity. All of the instructions you need are there - including materials, knitting/crocheting instructions, and shipping details. One of the statements on the site is: "Your stitches wrap a child in warmth and love." Conversely, doing something to help wraps ourhearts in warmth and love.

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Credit where credit is due...

All photos are by Dean and Melinda Ketelsen - even the really cool astrophotography ones. Granted, some pics have come from the Internet...such as pictures of actors, or of Miss Tohono O'odham, etc. However, the astronomy pics, as well as the bird pics are all original - compliments of Dean, and sometimes Melinda too! Layout, editing, and continual tweaking (I think they call that "desk top publishing"), well, that would be the work of "I know I can make this better" Melinda!